The present invention relates generally to water softeners and more specifically, to improvements in the water softener control device described in U.S. Pat. No. 3,891,552, the disclosure of which is incorporated herein by reference.
Water softeners of the "ion exchange" type typically include a resin tank through which hard water passes to exchange its "hard" ions of calcium and magnesium for "soft" sodium ions from the resin bed. Regeneration of the resin bed is required periodically to remove the accumulation of hard ions and replenish the supply of soft ions. Regeneration is effected by flushing a solution of salt through the resin bed.
U.S. Pat. No. 3,819,552 discloses a control valve for controlling a water softener having two ion exchange tanks. With this type of water softener/system, the soft water supply is not interrupted during regeneration because the exhausted tank is regenerated while the other tank is put "on-line". The newly regenerated tank is then left off-line until the on-line tank is exhausted.
The control valve of the prior patent included a valve-operating servo-system that was responsive to soft water usage. The servo-system controlled which of the ion exchange tanks was on-line and also controlled the regeneration sequence of the exhausted tank.
The principal components of the servo-system included a water usage indicator disc and a regeneration control disc mounted in the top of the control valve housing. Rotation of the indicator and control discs was effected through water driven turbines disposed in appropriate water flow paths. The turbines were directly coupled or geared to their respective discs through a reduction gear train. The water usage turbine was disposed in the path of soft water discharge so that turbine revolutions were directly proportional to the amount of water used. The regeneration control turbine was disposed in the path of a controlled or metered flow of water which impinged on the turbine only during a regeneration cycle.
Because the flow of large volumes of water must be translated to small movements in the water usage and regeneration control discs, relatively high reduction gear trains were employed between the turbines and the respective discs. Specifically, the final drive gear which engaged and rotated the regeneration control disc was driven at about one thirteen-thousandth the speed of the regeneration turbine, while the final drive gear that drove the water usage disc rotated about one forty-thousandth the speed of the water usage turbine. The large gear reductions necessary between the turbines and the discs required the use of rather complex gear trains having a large number of interconnecting gear wheels and minute gear teeth. If deposits or impurities carried by the water interfered with the gear trains driven by the water usage and regeneration turbines, the minute gear teeth employed in the gear trains could jam, thereby resulting in improperly softened water and requiring repair of the valve.
In the prior valve, the regeneration cycle was initiated by the concurrent rotation of both the water usage and regeneration control discs after the water usage disc had moved a predetermined distance. This concurrent movement was accomplished by using spaced gear segments on both the control and water usage discs which when aligned were concurrently driven by an idler pinion while the water usage disc was rotated by its drive pinion. This arrangement required a lost motion connection between the regeneration control disc and its associated drive pinion so that initial movement of the regeneration control disc would occur. Without this lost motion connection, movement of the regeneration control disc would be inhibited by the regeneration gear train and it could not be rotated by the water usage disc.
The foregoing construction of the prior valve prevented manual rotation of either the water usage or regeneration control discs. The substantial gear reductions between the turbines and the respective discs prevented rotation and made it impossible to manually sequence the control valve or initiate regeneration.